fix: apply #default annotation when it comes before #datatype

CHANGELOG.md

@@ -10,6 +10,7 @@
 1. [#720](https://github.com/influxdata/influxdb-client-python/pull/720): Prevent the `api_client` class from raising exceptions while the Python interpreter clears the client state during shutdown.
 1. [#723](https://github.com/influxdata/influxdb-client-python/pull/723): Export public names using generated `__all__` array in `__init__.py` as per reference documentation.
 1. [#725](https://github.com/influxdata/influxdb-client-python/pull/725): Start the `WritesRetry` `max_retry_time` at a request's first failure, so a strategy passed as `retries` to `InfluxDBClient` keeps retrying after `max_retry_time` has passed since it was created.
+1. [#732](https://github.com/influxdata/influxdb-client-python/pull/732): Apply the `#default` annotation in `FluxCsvParser` when it comes before `#datatype`.
 
 ## 1.50.0 [2026-01-23]
 

influxdb_client/client/flux_csv_parser.py

@@ -55,6 +55,7 @@ def __init__(self):
         self.start_new_table = False
         self.table = None
         self.groups = []
+        self.default_values = None
         self.parsing_state_error = False
 
 
@@ -185,6 +186,7 @@ def _parse_flux_response_row(self, metadata, csv):
                 self._insert_table(metadata.table, metadata.table_index)
                 metadata.table_index = metadata.table_index + 1
                 metadata.table_id = -1
+                metadata.default_values = None
             elif metadata.table is None:
                 raise FluxCsvParserException("Unable to parse CSV response. FluxTable definition was not found.")
 
@@ -196,7 +198,8 @@ def _parse_flux_response_row(self, metadata, csv):
                 metadata.groups = csv
 
             elif ANNOTATION_DEFAULT == token:
-                self.add_default_empty_values(metadata.table, csv)
+                # Applied with the column names: "#default" can come before "#datatype", which creates the columns
+                metadata.default_values = csv
 
             else:
                 # parse column names
@@ -207,6 +210,8 @@ def _parse_flux_response_row(self, metadata, csv):
                         self.add_data_types(metadata.table, list(map(lambda column: 'string', csv)))
                         metadata.groups = list(map(lambda column: 'false', csv))
                     self.add_groups(metadata.table, metadata.groups)
+                    if metadata.default_values is not None:
+                        self.add_default_empty_values(metadata.table, metadata.default_values)
                     self.add_column_names_and_tags(metadata.table, csv)
                     metadata.start_new_table = False
                     # Create DataFrame with default values

tests/test_FluxCSVParser.py

@@ -514,6 +514,53 @@ def test_parse_duplicate_column_names(self):
         self.assertEqual(25.3, tables[0].records[0].row[7])
 
 
+    def test_default_annotation_before_datatype(self):
+        data = "#default,_result,,,,,,,,,42,\n" \
+               "#group,false,false,true,true,true,true,true,true,false,false,false\n" \
+               "#datatype,string,long,dateTime:RFC3339,dateTime:RFC3339,string,string,string,string,long,long,string\n" \
+               ",result,table,_start,_stop,_field,_measurement,host,region,_value2,value1,value_str\n" \
+               ",,0,1677-09-21T00:12:43.145224192Z,2018-07-16T11:21:02.547596934Z,free,mem,A,west,121,,test\n"
+
+        tables = self._parse_to_tables(data=data)
+        self.assertEqual(1, tables.__len__())
+        self.assertEqual(11, tables[0].columns.__len__())
+        self.assertEqual("_result", tables[0].columns[0].default_value)
+        self.assertEqual("long", tables[0].columns[9].data_type)
+        self.assertTrue(tables[0].columns[2].group)
+        record = tables[0].records[0]
+        self.assertEqual("_result", record.values["result"])
+        self.assertEqual(42, record.values["value1"])
+        self.assertEqual(121, record.values["_value2"])
+
+    def test_default_annotation_before_datatype_more_tables(self):
+        data = "#default,first,,,\n" \
+               "#datatype,string,long,string,long\n" \
+               "#group,false,false,true,false\n" \
+               ",result,table,host,_value\n" \
+               ",,0,A,1\n" \
+               "\n" \
+               "#default,second,,,7\n" \
+               "#group,false,false,true,false\n" \
+               "#datatype,string,long,string,long\n" \
+               ",result,table,host,_value\n" \
+               ",,1,B,\n" \
+               "\n" \
+               "#datatype,string,long,string,long\n" \
+               "#group,false,false,true,false\n" \
+               ",result,table,host,_value\n" \
+               ",,2,C,\n"
+
+        tables = self._parse_to_tables(data=data)
+        self.assertEqual(3, tables.__len__())
+        self.assertEqual("first", tables[0].records[0].values["result"])
+        self.assertEqual(1, tables[0].records[0].values["_value"])
+        self.assertEqual("second", tables[1].records[0].values["result"])
+        self.assertEqual(7, tables[1].records[0].values["_value"])
+        self.assertTrue(tables[1].columns[2].group)
+        # defaults of a previous table must not leak into a table without #default
+        self.assertIsNone(tables[2].records[0].values["result"])
+        self.assertIsNone(tables[2].records[0].values["_value"])
+
     @staticmethod
     def _parse_to_tables(data: str, serialization_mode=FluxSerializationMode.tables,
                          response_metadata_mode=FluxResponseMetadataMode.full) -> TableList: